The common title for these twelve books of the English Bible is “minor prophets.” This title originated in Augustine’s time (late fourth century A.D.), but they are minor only in that they are each much shorter than the prophecies of Isaiah, Jeremiah, and Ezekiel (called “major prophets”). In Old and New Testament times, the Old Testament was called “The Law and the Prophets.” This title looked at the Old Testament from the standpoint of its divisions, but it also included the Law, the Prophets, and the Writings, which constituted a 24-book division.

I found these points from the ESV Study Bible article, “Introduction to the Prophetic Books”, helpful:

Unifying Themes in the Prophetic Books

The Prophetic Books include most of the OT’s greatest themes, preserving in written form for future generations the reasons Israel’s history happened as it did. Though the authors wrote in different times and under different circumstances, their messages are in theological harmony with one another and with other types of biblical books. Several interrelated ideas unify the prophetic message, making it possible for readers to find their bearings in some difficult literature. It is often helpful to decide which of the following themes the biblical author is stressing when one becomes puzzled by the content of the books.

First, the prophets assert that God has spoken through them. They clearly considered themselves God’s messengers and heralds, for they repeatedly preface their messages with the phrase, “Thus says Yahweh.” In this way the prophets are claiming that their books are the written word of God. Peter explains that the prophets “were carried along by the Holy Spirit” (2 Pet. 1:21). Just as God used Moses to write and preach so that Israel could know God’s will in his era, so God used the prophets in their generations. The prophets declared God’s instructions in two basic ways: word and symbol. Usually the prophets presented God’s word orally (e.g., Jer. 7:1–8:3) or in written form (e.g., Jer. 36:1–32) to varying types and sizes of audiences. Occasionally they performed symbolic acts that demonstrated God’s purposes. For example, Isaiah went naked and barefoot for three years to teach God’s people their future if they continued to seek help from other nations rather than from God (Isa. 20:1–6). Perhaps the saddest case of symbolic prophecy was Hosea’s marriage to unfaithful Gomer, which portrayed God’s relationship with unfaithful Israel (Hosea 1–3).

Second, the prophets affirm that God chose Israel for covenant relationship. The Pentateuch (the first five books of the OT) teaches that God chose Abraham and his family to bless all nations (Gen. 12:1–9), that he revealed salvation by grace to Abraham (Gen. 15:6), and that he assigned Moses to write a record of this revelation (Ex. 24:4). Furthermore, through Moses in Exodus–Deuteronomy he revealed the lifestyle that reflects that relationship. With these truths in mind, the prophets addressed Israel as a people with special responsibilities based on this special relationship (Jeremiah 2–6; Hosea 1–3; Amos 2:6–3:8; etc.). Through the prophets God revealed the success and failure of Israel’s attempts or lack of attempts to fulfill their confession of faith in God and their God-given role as a kingdom of priests charged with serving the nations (see Ex. 19:5–6).

Third, sadly, the prophets most often report that the majority of Israel has sinned against their God and his standards for their relationship. They have failed to trust God (Isa. 7:1–14). Thus, they have broken the Ten Commandments (cf. Ex. 20:1–17 and Jer. 7:1–15; Hos. 4:2). They have worshiped other gods (Ezek. 8:1–18). They have mistreated one another and failed to preserve justice among God’s people (Isa. 1:21–31). They have refused to repent (Amos 4:6–11). Of course, in these times there was always a faithful minority, called the “remnant” (see Isa. 4:3; 10:20–22; etc.), as the prophets’ ministries themselves demonstrate (see Hebrews 11).

Fourth, the prophets warn that judgment will eradicate sin. This judgment is often called the “day of the Lord” (Isa. 2:12–22; Joel 2:1–11; Zeph. 1:7–18; etc.; see note on Amos 5:18–20). This is a day in history, as when Jerusalem was destroyed by Babylon (Jer. 42:18), but it is also a day to come, when God will judge all the world’s inhabitants (Isa. 24:1–23). The prophets recorded these warnings in writing so readers can do what the prophets’ original audience usually failed to do—turn from sin to God.

Fifth, the prophets promise that renewal lies beyond the day of punishment that has occurred already in history and beyond the coming day that will bring history as we know it to a close. The coming of the Savior lies beyond the destruction of Israel and other such events. He will rule Israel and the nations, and he will bring peace and righteousness to the world (Isa. 9:2–7; 11:1–16). This Savior must suffer, die, and rise from the dead (Isa. 52:13–53:12). He will be “like a son of man,” and “the Ancient of Days” (God himself) will give him all the kingdoms of the world (Dan. 7:9–14). He will be the catalyst for a new covenant with Israel that will include all those, Jew or Gentile, whom God’s Spirit fills and changes (Jer. 31:31–40; 32:14–26; Ezek. 34:25–31; 36:22–32). This new people will serve him faithfully. Eventually he will cleanse the world of sin and recreate the earth (Isa. 65:17–25; 66:18–24; Zeph. 3:8–20). The creation now spoiled by sin will be whole again.

Christian, consider David’s prayer and its reality in our lives today. God is still great, rich, sovereign, and provider. Because of President Abraham Lincoln’s proclamation in 1863, we celebrate an annual day of Thanksgiving. Unfortunately Thanksgiving has degenerated into a day when we enjoy the bounty without praising the Benefactor. It has also been reduced to the eve of a day that extols materialism. Make this Thanksgiving a day filled with gratitude. Take some time to bless our Divine Benefactor for His provision of food, family, and leisure that so many of us enjoy on Thanksgiving. These are all gifts from the hands of a kind and benevolent God.

Evangelical Christians do believe in the existence, malevolence, and power of the Devil and demons. About these things, the New Testament is abundantly clear. We must resist any effort to “demythologize” the New Testament in order to deny the existence of these evil forces and beings. At the same time, we must recognize quickly that the Devil and demons are not accorded the powers often ascribed to them in popular piety. The Devil is indeed a threat, as Peter made clear when he warned: “Be sober-minded; be watchful. Your adversary the devil prowls around like a roaring lion, seeking someone to devour.” [1 Peter 5:8]

The New Testament is also clear that very real cases of demonic possession were encountered by Jesus and his followers. Jesus liberated afflicted individuals as he commanded the demons to flee, and they obeyed him. Likewise, the Apostle Paul performed exorcisms as he confronted the powers of evil and darkness in his ministry.

A closer look at the crucial passages involved reveals no rite of exorcism, however, just the name of Jesus and the proclamation of the Gospel. Likewise, there is no notion of a priestly ministry of ordained exorcists in the New Testament.

The weapons of our warfare are spiritual — and the power that the forces of darkness most fear is the name of Jesus, the authority of the Bible, and the power of his Gospel.

Evangelicals do not need a rite of exorcism, because to adopt such an invention would be to surrender the high ground of the Gospel. We are engaged in spiritual warfare every minute of every day, whether we recognize it or not. There is nothing the demons fear or hate more than evangelism and missions, where the Gospel pushes back with such supernatural power against their possessions, rendering them impotent and powerless. Every time a believer shares the Gospel and declares the name of Jesus, the demons and the Devil lose their power.

Furthermore, there is absolutely no New Testament evidence that a believer in Christ can be possessed by demons. Tormented and tempted? Sure. But never possessed. Once we are united with Christ by faith and given the gift of the indwelling Spirit, there is no way a demon can possess us. As the Apostle John reminds us, “Little children, you are from God and have overcome them, for he who is in you is greater than he who is in the world.” [1 John 4:4]

So, we should respect the power of the Devil and his demons, but never fear them. We do not need a rite of exorcism, only the name of Jesus. We are not given a priesthood of exorcists — for every believer is armed with the full promise of the Gospel, united with Christ by faith, and indwelt by the Holy Spirit.